(1) Field of the Invention
This invention generally relates to devices that reduce or eliminate the wobble of a bumper hitch insert inserted into a bumper hitch receiver. More specifically, this invention relates to shims and wedging devices that reduce the spacing between the inner surface of the receiver and the outer surface of the insert inserted into the receiver cavity. It includes a collar or sleeve configured to lie snugly adjacent the cavity formed by the inner wall of a bumper hitch receiver, and it includes a longitudinal gap allowing the sleeve to resiliently flex inwardly to facilitate insertion of the sleeve within the receiver, to assure contact with the inner wall of the receiver. The device may also include a flange or lip outstanding from the trailing edge of the sleeve, to prevent insertion within the receiver too far to allow easy extraction when no longer needed; a finger curl may also extend rearward from the sleeve, to facilitate extraction of the sleeve from the bumper hitch receiver.
Many vehicles today are equipped with receiver-type trailer hitches. Typically, these types of trailer hitches include a square receiver tube, normally 1½ or 2 inches in internal height and width, attached to the undercarriage of the vehicle. A second insert shank, which acts as a shank, includes outer dimensions slightly smaller than the internal dimensions of the receiver tube, so that it may be slideable inserted within the receiver tube. Once inserted, it is connected to the receiver by a lockpin or similar fastener inserted through aligned holes in both to prevent relative movement therebetween.
The rearward end of the insert shank may include a standard hitch-ball for engaging with the cupped tongue or hitch of a trailer or other wheeled vehicle. Another popular use for receiver hitches is to substitute a coupling device for the hitch-ball, for mounting racks and other accessories onto the vehicle. Bicycle carrier racks, ski carriers, barbeque grills, transport platforms, storage boxes and other types of carriers have been designed to use the above-described hitch insert shank to engage within a hitch receiver tube. This provides a universal system that allows a vehicle user to be able to use various trailers and carriers with a single coupling system.
One particular problem with the use of these conventional hitch assemblies is the clearance between the internal dimensions of the receiver tube and the external dimensions of the insert shank. These tubes by necessity must have sufficient clearance therebetween so that the shank is efficiently and easily telescopingly received within the receiver tube. Some space is desirable between the walls of the receiver tube and the walls of the shank, to allow easy attachment and detachment of the hitch. This space permits ease of coupling and decoupling between the receive tube and the shank. However, the clearance between the two causes relative movement therebetween, which potentially results in an shank that rattles or wobbles within the receiver tube during use. This rattle or wobble is an annoyance, at best, at best; and, at worst, it can distract the driver or cause damage to the trailer or the accessory. Moreover, with barbeque grills, bicycle racks, transport platforms and storage boxes that essentially set atop a vertical pole attached to (or integral with) the shank, slight axial movement of the shank side-to-side within the receiver translates into substantial pendular movement of whatever accessory is set atop the vertical pole; such substantial movement may cause damage to the accessory or its contents. Given the increasing prevalence of bumper-hitch accessories, there is an increased need for a durable device such as the invention disclosed herein, that is easily installed and uninstalled, and that eliminates or reduces the wobble and rattle of bumper hitch accessories mounted on a vehicle.
(2) Description of Related Art Including Information Disclosed 37 CFR 1.97 and 1.98
Devices to reduce wobble or rattling of trailer hitch inserts within receivers have been available for several years. Known in the art are the following, arguably related to the patentability of the present invention:
U.S. Pat. No.1st InventorDate of Patent/Publication5,333,888BallAug. 2, 19945,988,667YoungNov. 23, 19996,010,143SteinJan. 4, 20006,105,989LingerAug. 22, 20006,131,938SpeerOct. 17, 20006,142,502BreslinNov. 7, 20006,382,656Johnson. Jr.May 7, 20026,835,021McMillanDec. 28, 20046,974,147KoldaDec. 13, 20057,004,491AllsopFeb. 28, 20067,077,417ShoemakerJul. 18, 2006
U.S. Pat. No 6,382,656 issued to Johnson discloses an anti-rattle device for a trailer hitch comprising one or more flexible shims that are slideably inserted between the bumper hitch shaft and the receiver. The shims are essentially small rectangular sheets of plastic, preferably high density polycarbonate plastic; they must have sufficient strength and elasticity to flex without cracking upon being subjected to compression, bending and twisting forces between the bumper hitch shaft and the receiver. This patent indicates that the hitch is only subject to up and down rattling motions, since the lockpin naturally supports the hitch and prevents side to side motion.
U.S. Pat. No. 7,004,491 issued to Allsop discloses a wedge tightening device for hitch assemblies, comprising a wedge plate for insertion between the bumper hitch receiver's inner wall and the outer wall of the bumper hitch shaft. The wedge plate is wide enough to extend the width of the bumper hitch shaft, and bend partly around the notched corner of the bumper hitch shaft. There are aligned holes through one wall of the receiver, wedge plate and shaft; there is also a threaded nut attached to the inner wall of the shaft, for accepting a bolt screwed through the receiver and the wedge plate to essentially draw all three members into close, not-rattling contact.
None of the cited patents disclose an insertion sleeve having a longitudinal gap and resilient flexibility in its non-longitudinal direction, allowing the outwardly biased sleeve to resiliently flex inwardly; nor does any of the cited patents disclose a flange or lip outstanding from the trailing edge of the sleeve to prevent completion insertion into the receiver, or a curl member outstanding rearward therefrom to ease insertion and removal of the sleeve.